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Polyester is typically produced through a process known as polymerization. For polyethylene terephthalate (PET), the production process involves the chemical reaction between two primary raw materials: purified terephthalic acid (PTA) or dimethyl terephthalate (DMT) and monoethylene glycol (MEG). The production process includes the following steps:
Polyester resins are thermosetting and, as with other resins, cure exothermically. The use of excessive initiator especially with a catalyst present can, therefore, cause charring or even ignition during the curing process. Excessive catalyst may also cause the product to fracture or form a rubbery material.
The direct spinning process avoids the stage of solid polymer pellets. The polymer melt is produced from the raw materials, and then from the polymer finisher directly pumped to the spinning mill. Direct spinning is mainly applied during production of polyester fibers and filaments and is dedicated to high production capacity (>100 ton/day).
One process for making PET uses bis(2-hydroxyethyl) terephthalate, [citation needed] which can be synthesized by the esterification reaction between terephthalic acid and ethylene glycol with water as a byproduct (this is also known as a condensation reaction), or by transesterification reaction between ethylene glycol and dimethyl ...
Although many classes of fibers based on synthetic polymers have been evaluated as potentially valuable commercial products, four of them - nylon, polyester, acrylic and polyolefin - dominate the market. These four account for approximately 98 percent by volume of synthetic fiber production, with polyester alone accounting for around 60 percent ...
The synthetic resin for such processes is a monomer for making a plastic thermosetting polymer. During the setting process, the liquid monomer polymerizes into the polymer, thereby hardening into a solid. Single-monomer resins may be used in the process, which form homopolymers (polymers containing only one
The processes to make short-staple yarn (typically spun from fibers from 1.9 to 5.1 centimetres (0.75 to 2.0 in)) are blending, opening, carding, pin-drafting, roving, spinning, and—if desired—plying and dyeing. In long staple spinning, the process may start with stretch-break of tow, a continuous "rope" of synthetic fiber.
BoPET (biaxially oriented polyethylene terephthalate) is a polyester film made from stretched polyethylene terephthalate (PET) and is used for its high tensile strength, [1] chemical stability, [1] dimensional stability, [2] transparency [1] reflectivity, and electrical insulation. [1]